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INTRODUCTION

Passalus Fabricius, 1792 is the largest genus of Passali-dae, covering more than 150 species (Reyes-Castillo & Amat-Garcia, 1991), occurring about 60 species in Brazil (Fonseca & Reyes-Castillo, 2004). It is the most diverse genus of bess beetles in South America (Reyes-Castillo & Amat-Garcia, 1991) and is divided into three subgenera: P. (Pertinax) Kaup, 1869, P. (Mitrorhinus) Kaup, 1871 and P. (Passalus) Fabricius, 1792 (Luederwaldt, 1931). P. (Mitrorhinus) Kaup is characterized by having a single secondary tubercle on the front border of the head. It is the smallest of the three subgenera of Passalus, with only ten known species, with P. zikani Luerderwaldt, 1929, the last species described. After a long hiatus in descriptions of new species, we describe here Passalus (Mitrorhinus)

nodifer sp. nov., from the extreme west of the Brazilian Amazon.

MATERIAL AND METHODS

Two specimens collected during an expedition in the municipality of Feijó, Acre, Brazil, were compared with all species of the subgenus P. (Mitrorhinus) Kaup. The species that had affinities with P. nodifer sp. nov., were contrasted from the original description of these species as well as their synonym listed in Hincks & Dibb (1935). The description is based on the terminology proposed by Reyes-Castillo (1970) and the images were made using a Leica M165C stereomicroscope with a Leica DFC295 camera coupled and processed in the software LAS ver-

Bevilaqua, M. V. O., & Fonseca, C. R. V. (2017). New species of Passalus (Mitrorhinus) Kaup, 1871 (Coleoptera: Scarabaeoidea: Passalidae) from the extreme west of the Brazilian Amazon. Acta Zoológica Mexicana (n.s.), 33(2), 345-349.

ABSTRACT. Passalus (Mitrorhinus) nodifer sp. nov., from the ex-treme west of the Brazilian Amazon in the state of Acre is described and illustrated. The new species can be recognized by the head with conspicuous and strong single secondary tubercle; frontal ridges straight and well-marked; mandibles with two apical teeth; aedeagus with parameres reduced with large and rounded apical margin and basal piece with a deep V-shaped notched in the medial region.Key words: Passalinae, Acre, biodiversity, saproxilophages, taxon-omy.

Bevilaqua, M. V. O. y Fonseca, C. R. V. (2017). Nueva especie de Passalus (Mitrorhinus) Kaup, 1871 (Coleoptera: Scarabaeoidea: Passalidae) del extremo occidental de la Amazonia brasileña. Acta Zoológica Mexicana (n.s.), 33(2), 345-349.

RESUMEN. Passalus (Mitrorhinus) nodifer sp. nov., del extremo oc-cidental de la Amazonía brasileña en el estado de Acre se describe e ilustra. La nueva especie puede ser reconocida por la cabeza con el único tubérculo secundario conspicuo y fuerte; quillas frontales rec-tas y bien marcadas; mandíbulas con dos dientes apicales; edeago con parameros reducidos con margen apical grande y redondeada y pieza basal con una muesca profunda en forma de V en la región medial.Palabras clave: Passalinae, Acre, biodiversidad, saproxilófagos, taxo-nomía.

NEW SPECIES OF PASSALUS (MITRORHINUS) KAUP, 1871 (COLEOPTERA: SCARABAEOIDEA: PASSALIDAE) FROM THE EXTREME WEST

OF THE BRAZILIAN AMAZON

NUEVA ESPECIE DE PASSALUS (MITRORHINUS) KAUP, 1871 (COLEOPTERA: SCARABAEOIDEA: PASSALIDAE) DEL EXTREMO OESTE

DE LA AMAZONIA BRASILEÑA

Marcus Vinícius OLIVEIRA BEVILAQUA,* & Claudio Ruy VASCONCELOS DA FONSECA

Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade. Av. André Araújo, Nº 2936, caixa postal 478, CEP 69011-970, campus II, Aleixo Manaus, Amazonas, Brasil.

* Autor de correspondencia: ; .

Recibido: 15/11/2016; aceptado: 19/04/2017Editor responsable: Pedro Reyes Castillo.

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sion 4.2. The map was made with websoftware Simple-Mappr (Shorthouse, 2010).

RESULTS

Passalus (Mitrorhinus) nodifer sp. nov.(Figs. 1-6)Diagnosis: Head with conspicuous single second-ary tubercle as strong as the external tubercles; fron-tal ridges straight, well-marked, reaching the outer tubercles. Mandibles with two apical teeth. Small and comma-shaped mesosternum fossae. Narrow and gla-brous metasternal fossae. Aedeagus: parameres reduced with large and rounded apical margin, basal piece with a deep V-shaped notched in the medial region (ventral view).Description: medium size (25 to 26 mm body length). Elongated and flat body. Bright black color (Fig. 3).Head: In dorsal view (Fig. 1) labrum with anterior mar-gin almost straight, with setae and punctures scattered throughout the structure. Asymmetrical mandibles, with the left inner middle tooth wider than the right; apex of the mandible bidentate, the upper apical tooth larger and narrower; high, straight dorsal teeth, covering half of the back of the mandible. Deep and smooth mandibular fos-sae. Apex of lacinia bidentate. Antennal club with five la-mellae, the proximal lamella reduced, the second lamella one-third the size of the third, and the distal lamella slight-ly larger than lamellae three and four. Clypeus narrow and hidden under the frons. Head’s anterior angles developed, acute and smaller than external tubercles, these highly de-veloped, acute, oriented anteriorly. Single secondary tu-bercle located midway between the external tubercles and of the same length as these, but wider. Internal tubercles small and distinct, located at half the distance between the central tubercle and external tubercles. Frontal ridges elevated and weakly arched extending from the medial frontal structure, passing through the inner tubercles and reaching the outer tubercles. Frontal area transverse, gla-brous, chalice-shaped, delimited by the frontal ridges, with few punctures and a small triangular-shaped mam-elon (sensu Jiménez-Ferbans & Reyes-Castillo, 2014). Frontal middle structure falsus type, with small central tubercle and non-free apex; parietal tubercles large, low, sometimes inconspicuous, and not reaching the central tubercle. Frontal fossae glabrous, with no punctures and with little roughness. Ocular canthus developed, rough and rounded. Occipital groove strongly marked, arched

and smooth, extending to supraorbital tubercles. In ven-tral view (Fig. 2) hypostomal process slightly separated from mentum, smooth, shiny and glabrous. Mentum with punctuations throughout structure; middle area with protruding anterior margin; round, large and deep scars showing opaque punctuations; lobes of the mentum with punctures and setae mainly at the base. Ligula 3-toothed, medium tooth longer than lateral teeth; with large punc-tuations from which setae arise. Gula glabrous with small punctuations anteriorly. Labial palps with reduced proxi-mal segments, middle segment longer and of same length as distal segment.Thorax: Pronotum rectangular, same width as elytra, with few punctuations laterally, mostly associated with the lateral fossae. Very sparse pubescence formed by small setae mostly on the anterior and posterior border of the pronotum. Lateral pronotal groove not evident. Anterior pronotal groove well marked with strong punctures and extending up to just over 2/3 distance from lateral edge to median longitudinal groove. Anterior pronotal angles acute and conspicuous with very few setae on the ven-tral side. Longitudinal groove well defined and marked, extending for almost the entire length of the pronotum. Rhomboidal prosternelum with narrow apex, glabrous, opaque and porous texture. Mesoesternum with well-de-fined groove, small, comma-shaped and matte. Mesepi-sternum glabrous, very marked by small punctuations. Very narrow lateral metaesternal grooves, no punctuation or pubescence, with rough texture. Smooth and glabrous sternal disc, delimited by a group of punctures in the pos-terior medial area.Elytra: bright; shoulders glabrous. Striae narrower than the interstriae, marked with well-defined round punctua-tions in both the dorsal and the lateral striae. Epipleura glabrous.Legs: Femur I with very reduced pubescence, being appar-ent only by two rows of fine setae in the dorsal and lateral side; anterior marginal groove well-marked and narrow. Tibia I with a spur and very few setae along the external margin; incomplete dorsal groove; seven reduced spines on the outer side. Tibia II with reduced pubescence, with two rows of small setae. Tibia II and III with two spines on the inner margin.Abdomen: lateral groove not very marked, but very nar-row and complete. Aedeagus in ventral view (Fig. 4) with basal piece fused to parameres, phallobase with a deep V-shaped notched in the medial region. Medial lobe large occupying almost half of the entire aedeagus with two longitudinal sclerotized plates located near the

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Figures 1-6. Passalus (Mitrorhinus) nodifer sp. nov. 1. Head and anterior region of pronotum, in dorsal view (scale 20 mm); 2. Head in ventral view (scale 15 mm); 3. Habitus dorsal view (scale 50 mm); 4. Aedeagus in ventral view; 5. Aedeagus in dorsal view; 6. Aedeagus in lateral view

(scales 10 mm).

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edges, starting from the parameres and reaching the apex of the medial lobe (dorsal view Fig. 5). In lateral view (Fig. 6) the parameres are reduced, enlarged, and rounded at apex.Examined Material: HOLOTYPE ♂: BRAZIL: Acre, Feijó, interflúvio Tarauacá/Envira 8º10’03.28”S 70º30’09.27”W, 05-11/xi/2011, Fernando Pinto & Gleic Sá col. (Coleção de Invertebrados do Instituto Nacional de

Pesquisas da Amazônia - INPA). PARATYPE 1♀: same data of Holotype, except, 8º30’20.98”S 70º02’41.43”W.Geographical distribution: To date the geographical distribution of P. nodifer sp. nov., is restricted only to the type locality (Fig. 7).Etymology: The specific epithet derives from the Latin "nodus" which means "knot" referring to its notorious secondary tubercle.

Figure 7. Map with the type locality of Passalus (Mitrorhinus) nodifer sp. nov.

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DISCUSSION

Passalus (Mitrorhinus) nodifer sp. nov., is related to Pas-salus spinifer Percheron, 1841 because both have strong and high frontal ridges reaching the external tubercles, but in the case of P. spinifer Percheron, such ridges are sinu-ous, differing from P. nodifer sp. nov., by having straight front ridges. In addition, P. spinifer Percheron differ by having large, circular, deep and scored mesoesternal fos-sae; the metasternal disc is delimited by spaced punctua-tions not detached to the sides, while P. nodifer sp. nov., has smaller and narrower lateral metasternal fossae and the metasternal disc is well delimited by punctuations in the middle posterior region. It may also be closely related to Passalus lunaris Kaup, 1869, as both having mandibles with two terminal teeth and frontal ridges extending to the outer tubercles; however, P. nodifer sp. nov., has a shorter central tubercle and a non-free apex, low and sometimes inconspicuous parietal tubercles.

REMARKS

The subgenus P. (Mitrorhinus) Kaup as well as the other subgenera and sections of Passalus Fabricius are possibly not monophyletic in relation to genus, requiring urgent revision and phylogenetic studies in order to correctly

group the taxa as well as to define limits and degrees of kinship between the species. In the meantime, the great contrast in the number of P. (Mitrorhinus) Kaup species in comparison with other subgenera can be explained by the lack of taxonomic studies concerning the group.

REFERENCES CITED

Fonseca, C. R. V., & Reyes-Castillo, P. (2004). Synopsis on Passali-dae family (Coleoptera: Scarabaeoidea) of Brazil with description of a new species of Veturius Kaup, 1871. Zootaxa, 789, 1-26.

Hincks, W. D. & Dibb, J. R. (1935). Pars 142 Passalidae, pp. 1-142. In: W. Junk (Ed.). Coleopterorum Catalogus. S. Schenkling. The Hague.

Jiménez-Ferbans L. & Reyes-Castillo P. (2014). Description, phy-logeny and biogeography of Ameripassalus, a new Mesoamerican genus of Passalidae (Coleoptera). Invertebrate Systematics 28, 124 -144.

Luederwaldt, H. (1931). Monografia dos passalídeos do Brasil (Col.). Revista do Museu Paulista, 17, 1-262.

Reyes-Castillo, P. (1970). Coleoptera Passalidae: morfología y di-visión en grandes grupos: géneros americanos. Folia Entomológi-ca Mexicana, 20-22,1-240.

Reyes-Castillo, P. &. Amat-García, G. (1991). Notas sobre la taxono-mía y distribución de Passalidae (Insecta: Coleoptera) en Colom-bia y descripción de una nueva especie. Caldasia, 16, 501-508.

Shorthouse, D. P. (2010). SimpleMappr, an online tool to produce publication-quality point maps. Available at: http://www.simple-mappr.net. (accessed on April 2017).